Another user sent a similar question and I responded here:
https://lists.cs.wisc.edu/archive/condor-users/2012-January/msg00038.shtml
Simplistically, due to the changed security model in Vista and higher,
access to the video card is severely restricted in the session 0 that
Condor and jobs run in. Currently the only way to run a CUDA or any
job that requires a GPU on Windows using Condor is to run Condor as a
personal Condor. This however requires that a user be logged into the
machine to start up and keep Condor running. You also lose the
sandboxing from the user that Condor does when running as a service.